JSP请求地址重写

请求地址重写好处不在赘述。现在有开源框架支持，非常方便：urlrewrite，http://tuckey.org/urlrewrite/。具体实现也非常简单，首先下载他的jar包，放到lib里，并添加library。首先在web.xml里的最上面，所有filter最上面，添加：

<filter>
    <filter-name>UrlRewriteFilter</filter-name>
    <filter-class>org.tuckey.web.filters.urlrewrite.UrlRewriteFilter</filter-class>
</filter>
<filter-mapping>
    <filter-name>UrlRewriteFilter</filter-name>
    <url-pattern>*.aspx</url-pattern>
    <dispatcher>REQUEST</dispatcher>
    <dispatcher>FORWARD</dispatcher>
</filter-mapping>

*.aspx就是你要拦截的请求地址结尾。
然后再WEN-INF下新建urlrewrite.xml，内容为：

<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE urlrewrite PUBLIC "-//tuckey.org//DTD UrlRewrite 4.0//EN"
        "http://www.tuckey.org/res/dtds/urlrewrite4.0.dtd">

<!--

    Configuration file for UrlRewriteFilter
    http://www.tuckey.org/urlrewrite/

-->
<urlrewrite>

    <rule>
        <note>
                注释文本，映射规则说明
        </note>
        <from>^/(\w+)/(\w+)/(\w+)\.aspx$</from>
        <to type="forward">$2Action!$3.aspx</to>
    </rule>
    <outbound-rule>
        <note>
            The outbound-rule specifies that when response.encodeURL is called (if you are using JSTL c:url)
            the url /rewrite-status will be rewritten to /test/status/.

            The above rule and this outbound-rule means that end users should never see the
            url /rewrite-status only /test/status/ both in thier location bar and in hyperlinks
            in your pages.
        </note>
        <from>/rewrite-status</from>
        <to>/test/status/</to>
    </outbound-rule>


    <!--

    INSTALLATION

        in your web.xml add...

        <filter>
            <filter-name>UrlRewriteFilter</filter-name>
            <filter-class>org.tuckey.web.filters.urlrewrite.UrlRewriteFilter</filter-class>
            <init-param>
                <param-name>logLevel</param-name>
                <param-value>WARN</param-value>
            </init-param>
        </filter>
        <filter-mapping>
            <filter-name>UrlRewriteFilter</filter-name>
            <url-pattern>/*</url-pattern>
        </filter-mapping>

     EXAMPLES

     Redirect one url
        <rule>
            <from>/some/old/page.html</from>
            <to type="redirect">/very/new/page.html</to>
        </rule>

    Redirect a directory
        <rule>
            <from>/some/olddir/(.*)</from>
            <to type="redirect">/very/newdir/$1</to>
        </rule>

    Clean a url
        <rule>
            <from>/products/([0-9]+)</from>
            <to>/products/index.jsp?product_id=$1</to>
        </rule>
    eg, /products/1234 will be passed on to /products/index.jsp?product_id=1234 without the user noticing.

    Browser detection
        <rule>
            <condition name="user-agent">Mozilla/[1-4]</condition>
            <from>/some/page.html</from>
            <to>/some/page-for-old-browsers.html</to>
        </rule>
    eg, will pass the request for /some/page.html on to /some/page-for-old-browsers.html only for older
    browsers whose user agent srtings match Mozilla/1, Mozilla/2, Mozilla/3 or Mozilla/4.

    Centralised browser detection
        <rule>
            <condition name="user-agent">Mozilla/[1-4]</condition>
            <set type="request" name="browser">moz</set>
        </rule>
    eg, all requests will be checked against the condition and if matched
    request.setAttribute("browser", "moz") will be called.

    -->

</urlrewrite>

之后改web-inf里struts的拦截器，一定类似底下的：

 <!-- STRUTS2配置 -->
    <filter>
        <filter-name>struts2</filter-name>
        <filter-class>org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter</filter-class>
    </filter>
    <filter-mapping>
        <filter-name>struts2</filter-name>
        <url-pattern>*.aspx</url-pattern>
         <dispatcher>REQUEST</dispatcher>
         <dispatcher>FORWARD</dispatcher>
         <dispatcher>INCLUDE</dispatcher>
    </filter-mapping>

*.aspx可以换成你映射后的真实路径的结尾，struts配置文件中也要有相应的配置：

<constant name="struts.action.extension" value="aspx"></constant>

最关心的应该是映射规则，那里from节点是请求过来的地址，to节点是映射的真实地址，type是表示转发还是重定向，转发，struts拦截后可以获取参数，重定向则获取不到。2个节点可以是真实的地址，也可以用正则表达式匹配，最好是正则表达式，要不然写死人。